12v fuel plate & Allison AT545

[BookMobile]

That's my 98(215hp), 12v, 3000 governor springs, #10 plate slid forward, boosts 39lbs, clocked fuel pump & adjustable fuel pressure banjo bolt. Did the upgrades around 240k, currently about 513k. It dynos 432 HP & 860 ft/lbs torque at rear wheels. Other than a slightly heavier clutch, everything else is stock otherwise, no head studs, stock turbo, etc. I keep a close eye on the egts, never letting get above 1300°, although on heavy pulls up mountains, I've rested it on 1250° of a few straight minutes. It's nice to have the power & extra revs when you need it, but the longevity is all about how you drive it the rest of the time. In the case of the manual trans, the higher governor springs is probably the best upgrade I've ever done, I figured it would help with building the line pressure on the auto as well, but maybe not.

[Trailer2]

The 3000 springs will improve the drive ability the most. I would do the spring change and #10 plate in the middle of the slot and boost line restriction along with egt and boost gauges. If you don't have the gauges you are just guessing. The engine makes peak torque at less than 2000 and will probably kill a 545 pretty quick. Those engines also seem a lot weaker without a lockup converter. I have done quite a few cummins swaps and love working on them. If you do it right the first time your wallet will thank you.

[BookMobile]

I agree on the guages, I plan to have a pyro, boost, trans temp & either a manual fuel pressure gauge or atleast a warning light. I simply want to tweak the power & drivability with performance. I was hoping the 545 was underrated, just as a nv4500 is rated for 460ft/lbs torque, but those seem to handle over twice that in most cases.

[Trailer2]

If it were me I would not use any trans without a lockup converter. With or without overdrive. If u go through all the work of doing the swap with a trans that is on the edge of its hp rating and it fails, then what.

[Tango]

I have to go with the general consensus here. The AT545 was a workhorse in its' day and could last a lifetime. But...only if you stayed within it's limits and never overheated it or pushed it beyond its' HP & torque limits. Was never a "great" tranny and I would not consider investing a dime in one today, but if treated kindly...I could probably live with one.

But if you want more power, you are going to need more transmission.

[BookMobile]

OK. I guess I'll do more minor mods, obviously install a big oil cooler for it too. The engine & trans are still in the big flatnose, maybe it'll feel a little stouter in the lighter/shorter Bookmobile.